BOSTON BATTLER: Kevin Garnett and the Celtics figure to make life difficult for the Knicks when they meet in first round of NBA playoffs starting tomorrow. Photo: Getty Images

There’s always a but when talking about this season’s NBA playoffs.

The Knicks are the hottest team in the league and are well-positioned as the No. 2 seed, but … The Nets have had an impressive first season in Brooklyn and Deron Williams is playing his best basketball of the season, but … That but is the defending champion Heat — the team the Nets and the Knicks likely will have to get through to reach the NBA Finals.

“Sooner or later you’ve got to play Miami. It is what it is,” MSG Network Knicks analyst Walt “Clyde” Frazier said. “The main thing is confidence. You’ve got to believe.”

But before either local team has to worry about LeBron James, Dwyane Wade and company there is series to be won. The second-seeded Knicks open the playoffs tomorrow afternoon against the rival Celtics, while the Nets open at night versus the Bulls in the 4-5 matchup. If the Nets get past the defensive-minded Bulls, they likely would see the Heat in the second round, unless the Bucks pull a monumental upset, and the Knicks would have to reach the conference final before making a trip to South Beach.

The Knicks took three of four from Boston during the regular season, but the Celtics, with veterans Paul Pierce and Kevin Garnett, have a championship pedigree.

“They are going to be a formidable opponent, the Knicks know that,” Frazier said. “During the regular season, the Knicks distinguished themselves and won a couple in Boston. It’s a different scenario when you get into the playoffs because they had guys out, we had guys out. Now, all these guys will be ready.

“They know who Pierce is. They know Garnett. They know [Carmelo Anthony]. So, there are no surprises anymore.”

What surprised some is how the Knicks resurrected their season following four straight double-digit losses to open a mid-March trip out West. The team won 15 of 16 games before resting its starters for its final two games, supplanting the previously scorching Heat as the most torrid team in the league. It has helped give the team the belief it can beat the Celtics, Heat or anyone else.

“I think they feel that way. They are exuding that kind of confidence right now,” Frazier said of the Knicks, who will have banged-up big men Tyson Chandler and Kenyon Martin back for the postseason.

“Believing is half the battle. And they still don’t know the advantage of the home crowd. This team has yet to be deep in the playoffs. They don’t know how provocative a New York crowd can be in propelling a team. Honestly, I know that with the Willis Reed game, the way he came out, and provided an impetus for the game that I had.

“The Celtics know. Doc Rivers knows. He’s a former Knick. He knows how rough the Garden can be.”

The impetus for the Knicks’ late-season surge has been the dominant play of Anthony, who finished the season as the NBA’s scoring champ. Frazier credits a slimmed-down Anthony as the reason for his MVP-caliber play.

“He has a lot of energy now to play defense, to rebound,” Frazier said. “I thought in the past down the stretch he would kind of run out of gas. The last 5-10 minutes he would be a little lethargic, which is conditioning. You can see the difference with the quickness in his step and the way he is overwhelming guys.”